Hi,
v3 updated to current HEAD.
Named blurdetect filter now.
Minor fixes on allocation and removed -f option.
Please make this per plane filtering, with default to measure only first
plane.
done in v4.
(Will add Changelog, version.h and fate test once the filter itself looks ok)
Thanks,
Thilo
From 6411603fe86d4fb6a781aec2ff48e48be12d269e Mon Sep 17 00:00:00 2001
From: Thilo Borgmann <thilo.borgm...@mail.de>
Date: Tue, 5 Apr 2022 10:54:19 +0200
Subject: [PATCH v4 2/2] lavfi: Add blurdetect filter
---
doc/filters.texi | 52 +++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_blurdetect.c | 394 ++++++++++++++++++++++++++++++++++++
4 files changed, 448 insertions(+)
create mode 100644 libavfilter/vf_blurdetect.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 636c80dbff..c6d4537804 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -7990,6 +7990,58 @@ tblend=all_mode=grainextract
@subsection Commands
This filter supports same @ref{commands} as options.
+@anchor{blurdetect}
+@section blurdetect
+
+Determines blurriness of frames without altering the input frames.
+
+Based on Marziliano, Pina, et al. "A no-reference perceptual blur metric."
+Allows for a block-based abbreviation.
+
+The filter accepts the following options:
+
+@table @option
+@item low
+@item high
+Set low and high threshold values used by the Canny thresholding
+algorithm.
+
+The high threshold selects the "strong" edge pixels, which are then
+connected through 8-connectivity with the "weak" edge pixels selected
+by the low threshold.
+
+@var{low} and @var{high} threshold values must be chosen in the range
+[0,1], and @var{low} should be lesser or equal to @var{high}.
+
+Default value for @var{low} is @code{20/255}, and default value for @var{high}
+is @code{50/255}.
+
+@item radius
+Define the radius to search around an edge pixel for local maxima.
+
+@item block_pct
+Determine blurriness only for the most significant blocks, given in percentage.
+
+@item block_width
+Determine blurriness for blocks of width @var{block_width}. If set to any
value smaller 1, no blocks are used and the whole image is processed as one no
matter of @var{block_height}.
+
+@item block_height
+Determine blurriness for blocks of height @var{block_height}. If set to any
value smaller 1, no blocks are used and the whole image is processed as one no
matter of @var{block_width}.
+
+@item planes
+Set planes to filter. Default is first only.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Determine blur for 80% of most significant 32x32 blocks:
+@example
+blurdetect=block_width=32:block_height=32:block_pct=80
+@end example
+@end itemize
+
@section bm3d
Denoise frames using Block-Matching 3D algorithm.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 006e59b2bd..6332a6f799 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -195,6 +195,7 @@ OBJS-$(CONFIG_BLACKDETECT_FILTER) +=
vf_blackdetect.o
OBJS-$(CONFIG_BLACKFRAME_FILTER) += vf_blackframe.o
OBJS-$(CONFIG_BLEND_FILTER) += vf_blend.o framesync.o
OBJS-$(CONFIG_BLEND_VULKAN_FILTER) += vf_blend_vulkan.o framesync.o
vulkan.o vulkan_filter.o
+OBJS-$(CONFIG_BLURDETECT_FILTER) += vf_blurdetect.o edge_common.o
OBJS-$(CONFIG_BM3D_FILTER) += vf_bm3d.o framesync.o
OBJS-$(CONFIG_BOXBLUR_FILTER) += vf_boxblur.o boxblur.o
OBJS-$(CONFIG_BOXBLUR_OPENCL_FILTER) += vf_avgblur_opencl.o opencl.o \
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 9fbaaacf47..2667d153ad 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -183,6 +183,7 @@ extern const AVFilter ff_vf_blackdetect;
extern const AVFilter ff_vf_blackframe;
extern const AVFilter ff_vf_blend;
extern const AVFilter ff_vf_blend_vulkan;
+extern const AVFilter ff_vf_blurdetect;
extern const AVFilter ff_vf_bm3d;
extern const AVFilter ff_vf_boxblur;
extern const AVFilter ff_vf_boxblur_opencl;
diff --git a/libavfilter/vf_blurdetect.c b/libavfilter/vf_blurdetect.c
new file mode 100644
index 0000000000..71e46fa962
--- /dev/null
+++ b/libavfilter/vf_blurdetect.c
@@ -0,0 +1,394 @@
+/*
+ * Copyright (c) 2021 Thilo Borgmann <thilo.borgmann _at_ mail.de>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * No-reference blurdetect filter
+ *
+ * Implementing:
+ * Marziliano, Pina, et al. "A no-reference perceptual blur metric."
Proceedings.
+ * International conference on image processing. Vol. 3. IEEE, 2002.
+ *
https://infoscience.epfl.ch/record/111802/files/14%20A%20no-reference%20perceptual%20blur%20metric.pdf
+ *
+ * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixelutils.h"
+#include "libavutil/motion_vector.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+#include "edge_common.h"
+
+static int comp(const void *a,const void *b)
+{
+ float x = *(float*)a;
+ float y = *(float*)b;
+ if (x > y) return 1;
+ if (x < y) return -1;
+ return 0;
+}
+
+typedef struct BLRContext {
+ const AVClass *class;
+
+ int hsub, vsub;
+ int nb_planes;
+
+ float low, high;
+ uint8_t low_u8, high_u8;
+ int radius; // radius during local maxima detection
+ int block_pct; // percentage of "sharpest" blocks in the image to
use for bluriness calculation
+ int block_width; // width for block abbreviation
+ int block_height; // height for block abbreviation
+ int planes; // number of planes to filter
+
+ double blur_total;
+ uint64_t nb_frames;
+
+ float *blks;
+ uint8_t *filterbuf;
+ uint8_t *tmpbuf;
+ uint16_t *gradients;
+ char *directions;
+} BLRContext;
+
+#define OFFSET(x) offsetof(BLRContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption blr_options[] = {
+ { "high", "set high threshold", OFFSET(high), AV_OPT_TYPE_FLOAT,
{.dbl=30/255.}, 0, 1, FLAGS },
+ { "low", "set low threshold", OFFSET(low), AV_OPT_TYPE_FLOAT,
{.dbl=15/255.}, 0, 1, FLAGS },
+ { "radius", "search radius for maxima detection", OFFSET(radius),
AV_OPT_TYPE_INT, {.i64=50}, 1, 100, FLAGS },
+ { "block_pct", "block pooling threshold when calculating blurriness",
OFFSET(block_pct), AV_OPT_TYPE_INT, {.i64=80}, 1, 100, FLAGS },
+ { "block_width", "block size for block-based abbreviation of
blurriness", OFFSET(block_width), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX,
FLAGS },
+ { "block_height", "block size for block-based abbreviation of
blurriness", OFFSET(block_height), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX,
FLAGS },
+ { "planes", "set planes to filter", OFFSET(planes),
AV_OPT_TYPE_INT, {.i64=1}, 0, 15, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(blr);
+
+static av_cold int blr_init(AVFilterContext *ctx)
+{
+ BLRContext *blr = ctx->priv;
+
+ blr->low_u8 = blr->low * 255. + .5;
+ blr->high_u8 = blr->high * 255. + .5;
+
+ return 0;
+}
+
+static int blr_config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ BLRContext *blr = ctx->priv;
+ const int bufsize = inlink->w * inlink->h;
+ const AVPixFmtDescriptor *pix_desc;
+
+ pix_desc = av_pix_fmt_desc_get(inlink->format);
+ blr->hsub = pix_desc->log2_chroma_w;
+ blr->vsub = pix_desc->log2_chroma_h;
+ blr->nb_planes = av_pix_fmt_count_planes(inlink->format);
+
+ if (blr->block_width < 1 || blr->block_height < 1) {
+ blr->block_width = inlink->w;
+ blr->block_height = inlink->h;
+ }
+
+ blr->tmpbuf = av_malloc(bufsize);
+ blr->filterbuf = av_malloc(bufsize);
+ blr->gradients = av_calloc(bufsize, sizeof(*blr->gradients));
+ blr->directions = av_malloc(bufsize);
+ blr->blks = av_calloc((inlink->w / blr->block_width) * (inlink->h /
blr->block_height),
+ sizeof(*blr->blks));
+
+ if (!blr->tmpbuf || !blr->filterbuf || !blr->gradients ||
+ !blr->directions || !blr->blks)
+ return AVERROR(ENOMEM);
+
+ return 0;
+}
+
+// edge width is defined as the distance between surrounding maxima of the
edge pixel
+static float edge_width(BLRContext *blr, int i, int j, int8_t dir, int w, int
h,
+ int edge, const uint8_t *src, int src_linesize)
+{
+ float width = 0;
+ int dX, dY;
+ int sign;
+ int tmp;
+ int p1;
+ int p2;
+ int k, x, y;
+ int edge1;
+ int edge2;
+ float luma1 = 0.0; // average luma difference per edge pixel
+ float luma2 = 0.0;
+ int radius = blr->radius;
+
+ switch(dir)
+ {
+ case DIRECTION_HORIZONTAL: dX = 1; dY = 0; break;
+ case DIRECTION_VERTICAL: dX = 0; dY = 1; break;
+ case DIRECTION_45UP: dX = 1; dY = -1; break;
+ case DIRECTION_45DOWN: dX = 1; dY = 1; break;
+ }
+ if (dir == DIRECTION_HORIZONTAL) return 0;
+
+ // determines if search in direction dX/dY is looking for a maximum or
minimum
+ sign = src[j * src_linesize + i] > src[(j - dY) * src_linesize + i - dX] ?
1 : -1;
+
+ // search in -(dX/dY) direction
+ for (k = 0; k < radius; k++)
+ {
+ x = i - k*dX;
+ y = j - k*dY;
+ p1 = y * src_linesize + x;
+ x -= dX;
+ y -= dY;
+ p2 = y * src_linesize + x;
+ if (x < 0 || x >= w || y < 0 || y >= h)
+ return 0;
+
+ tmp = (src[p1] - src[p2]) * sign;
+
+ if (tmp <= 0) // local maximum found
+ break;
+
+ luma1 += tmp;
+ }
+ if (k > 0) luma1 /= k;
+ edge1 = k;
+ width += k;
+
+ // search in +(dX/dY) direction
+ for (k = 0; k < radius; k++)
+ {
+ x = i + k * dX;
+ y = j + k * dY;
+ p1 = y * src_linesize + x;
+ x += dX;
+ y += dY;
+ p2 = y * src_linesize + x;
+ if (x < 0 || x >= w || y < 0 || y >= h)
+ return 0;
+
+ tmp = (src[p1] - src[p2]) * sign;
+
+ if (tmp >= 0) // local maximum found
+ break;
+
+ luma2 -= tmp;
+ }
+ if (k > 0) luma2 /= k;
+ edge2 = k;
+ width += k;
+
+ // for 45 degree directions approximate edge width in pixel units: 0.7 ~=
sqrt(2)/2
+ if (dir == DIRECTION_45UP || dir == DIRECTION_45DOWN)
+ width *= 0.7;
+
+ return width;
+}
+
+static float calculate_blur(BLRContext *blr, int w, int h, int hsub, int vsub,
+ uint8_t* dir, int dir_linesize,
+ uint8_t* dst, int dst_linesize,
+ uint8_t* src, int src_linesize)
+{
+ float total_width = 0.0;
+ int block_count;
+ double block_total_width;
+
+ int i, j;
+ int blkcnt = 0;
+
+ float *blks = blr->blks;
+ float block_pool_threshold = blr->block_pct / 100.0;
+
+ int block_width = AV_CEIL_RSHIFT(blr->block_width, hsub);
+ int block_height = AV_CEIL_RSHIFT(blr->block_height, vsub);
+ int brows = h / block_height;
+ int bcols = w / block_width;
+
+ for (int blkj = 0; blkj < brows; blkj++) {
+ for (int blki = 0; blki < bcols; blki++) {
+ block_total_width = 0.0;
+ block_count = 0;
+ for (int inj = 0; inj < block_height; inj++) {
+ for (int ini = 0; ini < block_width; ini++) {
+ i = blki * block_width + ini;
+ j = blkj * block_height + inj;
+
+ if (dst[j * dst_linesize + i] > 0) {
+ float width = edge_width(blr, i, j,
dir[j*dir_linesize+i],
+ w, h, dst[j*dst_linesize+i],
+ src, src_linesize);
+ if (width > 0.001) { // throw away zeros
+ block_count++;
+ block_total_width += width;
+ }
+ }
+ }
+ }
+ // if not enough edge pixels in a block, consider it smooth
+ if (block_total_width >= 2) {
+ blks[blkcnt] = block_total_width / block_count;
+ blkcnt++;
+ }
+ }
+ }
+
+ // simple block pooling by sorting and keeping the sharper blocks
+ qsort(blks, blkcnt, sizeof(*blks), comp);
+ blkcnt = ceil(blkcnt * block_pool_threshold);
+ for (int i = 0; i < blkcnt; i++) {
+ total_width += blks[i];
+ }
+
+ return total_width / blkcnt;
+}
+
+static void set_meta(AVDictionary **metadata, const char *key, float d)
+{
+ char value[128];
+ snprintf(value, sizeof(value), "%f", d);
+ av_dict_set(metadata, key, value, 0);
+}
+
+static int blr_filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ BLRContext *blr = ctx->priv;
+ AVFilterLink *outlink = ctx->outputs[0];
+
+ const int inw = inlink->w;
+ const int inh = inlink->h;
+
+ uint8_t *tmpbuf = blr->tmpbuf;
+ uint8_t *filterbuf = blr->filterbuf;
+ uint16_t *gradients = blr->gradients;
+ int8_t *directions = blr->directions;
+
+ float blur = 0.0f;
+ int nplanes = 0;
+ AVDictionary **metadata;
+ metadata = &in->metadata;
+
+ for (int plane = 0; plane < blr->nb_planes; plane++) {
+ int hsub = plane == 1 || plane == 2 ? blr->hsub : 0;
+ int vsub = plane == 1 || plane == 2 ? blr->vsub : 0;
+ int w = AV_CEIL_RSHIFT(inw, hsub);
+ int h = AV_CEIL_RSHIFT(inh, vsub);
+
+ if (!((1 << plane) & blr->planes))
+ continue;
+
+ nplanes++;
+
+ // gaussian filter to reduce noise
+ ff_gaussian_blur(w, h,
+ filterbuf, w,
+ in->data[plane], in->linesize[plane]);
+
+ // compute the 16-bits gradients and directions for the next step
+ ff_sobel(w, h, gradients, w, directions, w, filterbuf, w);
+
+ // non_maximum_suppression() will actually keep & clip what's
necessary and
+ // ignore the rest, so we need a clean output buffer
+ memset(tmpbuf, 0, inw * inh);
+ ff_non_maximum_suppression(w, h, tmpbuf, w, directions, w, gradients,
w);
+
+
+ // keep high values, or low values surrounded by high values
+ ff_double_threshold(blr->low_u8, blr->high_u8, w, h,
+ tmpbuf, w, tmpbuf, w);
+
+ blur += calculate_blur(blr, w, h, hsub, vsub, directions, w,
+ tmpbuf, w, filterbuf, w);
+ }
+
+ if (nplanes)
+ blur /= nplanes;
+
+ blr->blur_total += blur;
+
+ // write stats
+ av_log(ctx, AV_LOG_VERBOSE, "blur: %.7f\n", blur);
+
+ set_meta(metadata, "lavfi.blur", blur);
+
+ blr->nb_frames++;
+
+ return ff_filter_frame(outlink, in);
+}
+
+static av_cold void blr_uninit(AVFilterContext *ctx)
+{
+ BLRContext *blr = ctx->priv;
+
+ if (blr->nb_frames > 0) {
+ int nb_frames = blr->nb_frames;
+ av_log(ctx, AV_LOG_INFO, "blur mean: %.7f\n",
+ blr->blur_total / nb_frames);
+ }
+
+ av_freep(&blr->tmpbuf);
+ av_freep(&blr->filterbuf);
+ av_freep(&blr->gradients);
+ av_freep(&blr->directions);
+ av_freep(&blr->blks);
+}
+
+static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV420P,
AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE };
+
+static const AVFilterPad blr_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = blr_config_input,
+ .filter_frame = blr_filter_frame,
+ },
+};
+
+static const AVFilterPad blr_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+};
+
+AVFilter ff_vf_blurdetect = {
+ .name = "blurdetect",
+ .description = NULL_IF_CONFIG_SMALL("Blurdetect filter."),
+ .priv_size = sizeof(BLRContext),
+ .init = blr_init,
+ .uninit = blr_uninit,
+ FILTER_PIXFMTS_ARRAY(pix_fmts),
+ FILTER_INPUTS(blr_inputs),
+ FILTER_OUTPUTS(blr_outputs),
+ .priv_class = &blr_class,
+ .flags = AVFILTER_FLAG_METADATA_ONLY,
+};
+
--
2.20.1 (Apple Git-117)
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